Conventionally, in an image forming apparatus, many mechanisms to transfer charged powdery developers (so called a dry type toner: hereinafter simply referred to as “a toner”) using traveling wave electric fields have been known (for example, Japanese Patent Provisional Publication No. SHO 59-181371, or Japanese Patent Provisional Publication No. HEI 05-19616).
Such a transferring mechanism includes a toner transfer body which is configured such that a plurality of linear transfer electrodes is provided on a substrate of an insulator. In this configuration, multi-phase alternating current voltages are sequentially applied to the plurality of linear electrodes, thereby forming traveling wave electric fields. Charged developers are transferred in a predetermined direction by effects of the traveling wave electric fields.